Passenger seats of automobiles or trains, various kinds of sofas, office chairs, and the like are often formed by attaching a skin material such as fiber fabric or natural or synthetic leather to the surface of a cushion body (foaming body) molded in a predetermined shape by using a foam resin material. The cushion body used in these various seats often has a bent surface composed of convex-concave shapes satisfying human engineering factors in order to maintain a seating posture which provides no fatigue despite long-hour seating.
When a skin material is attached to the surface of a cushion body, after molding the cushion body in a desired shape, a method of covering and fixing a skin material to the surface of the obtained cushion body is often employed. In particular, in this case, a molded surface fastener is generally used as means for fixing the surface of the cushion body and a bottom surface of the skin material.
A molded surface fastener has a configuration in which a plurality of engaging elements (male engaging elements, for example) are disposed on one surface (first surface) of a base portion made from a thermoplastic resin, and such a molded surface fastener is integrally molded so that the engaging elements are exposed to the surface of the cushion body when the cushion body is molded. Moreover, a plurality of female engaging elements configured to be fastened to the engaging elements of the molded surface fastener are formed on the bottom surface of the skin material that covers the cushion body.
After the skin material covers the cushion body to which the molded surface fastener is integrated, the female engaging elements (loop-shaped engaging elements) disposed on the bottom surface of the skin material are pressed against the male engaging elements of the molded surface fastener disposed on the surface of the cushion body, whereby the skin material is fastened to the molded surface fastener. In this manner, the skin material is easily fixed to the surface of the cushion body along the convex-concave shapes of the surface, and the skin material is prevented from floating from the cushion body.
Examples of such a molded surface fastener integrated to the cushion body for fixing the skin material are disclosed in U.S. Pat. No. 6,720,059 (Patent Document 1) and WO 2012/025980 (Patent Document 2).
In such a molded surface fastener described in Patent Documents 1 and 2, a plurality of hook-shaped engaging elements stand on a long and thin plate-shaped substrate portion to form an engaging region in which these hook-shaped engaging elements can engage with loop-shaped engaging elements. In this case, the engaging region is formed in a whole length direction of the substrate portion.
On left and right side edge portions in a width direction of the substrate portion, a pair of left and right resin intrusion barrier portions stand along the length direction so as to hold the engaging region between them.
Further, in the molded surface fastener of the Patent Document 2, a plurality of hook-shaped engaging elements are disposed in lines in the length direction and in the width direction, and lateral wall portions are disposed between the resin intrusion barrier portion and the engaging region and between engaging elements adjacent with each other in the width direction.
In a case that a cushion body is foamed and molded to integrate the molded surface fastener as in Patent Document 1 or Patent Document 2, the molded surface fastener is held at an inner surface (cavity surface) of a molding die for molding the cushion body, and a foam resin material is injected into an inner space (cavity) of the molding die. In this case, the engaging regions of the molded surface fastener can be blocked from the inner space of the molding die by the left and right resin intrusion barrier portions disposed at the molded surface fastener by that the left and right resin intrusion barrier portions of the molded surface fastener is closely contacted with the inner surface of the molding die.
As the foam molding is performed by injecting the foam resin material of the cushion body into the molding die in a state that the left and right resin intrusion barrier portions of the molded surface fastener is closely contacted with the inner surface of the molding die, the foam resin material can be prevented from flowing into the engaging region from the width direction over the left and right resin intrusion barrier portions, which enables manufacturing the cushion body to which the molded surface fastener is integrated. Further, since the above-mentioned lateral wall portions are disposed in the molded surface fastener of Patent Document 2, the foam resin material can be effectively prevented from flowing into the engaging regions from the length direction over the lateral wall portions disposed at both end edge portions in the length direction of the substrate portion.
Therefore, in the cushion body to which the molded surface fastener of Patent Document 1 or Patent Document 2 is integrated, engaging elements of the molded surface fastener can be prevented from being buried by the foaming body, and a plurality of engaging elements can be exposed on a surface of the cushion body. Thereby, in the cushion body to which the molded surface fastener is integrated, a desired engaging force by a plurality of engaging elements disposed in the engaging regions can be stably exerted, and loop-shaped engaging elements provided on a skin material can be stably engaged.
Patent Document 1 also discloses a molded surface fastener in which a plurality of peripheral wall portions disposed along the length direction with intervals, a plurality of engaging elements disposed on an inside of respective peripheral wall portions and a pair of left and right resin intrusion barrier portions standing along the length direction at left and right side edge portions of the substrate portion so as to hold the peripheral wall portions and the engaging elements between them are provided on a long and thin plate-shaped substrate portion, as an Embodiment (see FIGS. 13 and 14 of Patent Document 1).
Meanwhile, a cushion body used for a seat and the like disposed on automobiles or trains sometimes has a bent surface composed of a convex-concave shape, as mentioned above. When a molded surface fastener is attached to such a cushion body, the molded surface fastener may be integrated with the cushion body in a state that the molded surface fastener is bent in a thickness direction or a width direction, depending on a usage of the cushion body or a design of a product.
However, in the above-mentioned molded surface fastener according to Patent Document 1 or Patent Document 2, the substrate portion in which a plurality of the engaging elements and the left and right resin intrusion barrier portions are provided are formed in a thin plate-shaped and in a long shape. Therefore, it cannot be bent in the width direction. Accordingly, the molded surface fastener of Patent Document 1 or Patent Document 2 has a defect that it cannot be applied to a cushion body in which the molded surface fastener needs to be integrated in a bent state in the width direction.
In contrast, a molded surface fastener which can be integrated to a cushion body in a bent state in the width direction are disclosed in, for example, JP2011-143231A (Patent Document 3), WO2013/061423A (Patent Document 4) and US2013-0149490A (Patent Document 5).
The molded surface fastener recited in Patent Document 3, for example, is configured such that substantially fishbone-shaped hook members are adhered to a base made of polystyrene foam or nonwoven fabric. In this case, the base is configured to have left and right side wall portions disposed in parallel along the length direction and left and right flap portions extending outward from the side wall portions, and to be able to extend and shrink in the width direction.
The substantially fishbone-shaped hook members in Patent Document 3 are fixed between the left and right side wall portions of the base. The hook members also have a center rib extending along the length direction and an engaging portion extending in the width direction from the both sides of the center rib and in which a plurality of hook-shaped engaging elements are disposed on an upper surface. Constant intervals are provided between adjacent engaging portions in the length direction.
Such a molded surface fastener of Patent Document 3 can be integrated to a cushion body in a bent state in the width direction. It also can prevent the foam resin material from flowing into the engaging portions of the hook members over the left and right side wall portions of the base and intruding from the width direction when the cushion body is foamed and molded.
The molded surface fastener described in Patent Document 4 is configured that a plurality of surface fastener members on which a plurality of hook-shaped engaging elements stand on an upper surface of the flat plate-shaped substrate portion are connected along the length direction via connecting portions (monofilament) having flexibility. In each surface fastener member, a pair of left and right vertical barrier portions standing along the length direction at left and right side edge portions of the substrate portion and two rows of first and second lateral wall portions standing along the width direction at front and rear end edge portions of the substrate portion are disposed so as to surround an engaging region formed of a plurality of engaging elements.
Such a molded surface fastener of Patent Document 4 can also be integrated to a cushion body in a bent state in the width direction. Further, since the pair of left and right vertical barrier portions and front and rear first and second lateral wall portions are disposed in each surface fastener member, the foam resin material can be prevented from intruding into the engaging region of each surface fastener member when the cushion body is foamed and molded.
The molded surface fastener described in Patent Document 5 as an Embodiment (see FIGS. 5A and 5B of Patent Document 5) is configured such that a plurality of fastening segments in which a plurality of hook-shaped engaging elements stand are connected by flexible neck portions along the length direction. Each fastening segment has a substrate portion, a barrier portion standing along the length direction on the substrate portion, a segment wall portion disposed along the length direction on an outside of the barrier portion and a lateral wall portion standing along the width direction on the substrate portion.
In each fastening segment, an engaging region which is surrounded by the left and right barrier portions and the front and rear lateral wall portions, and in which the foam resin material can be prevented from intruding when the cushion body is foamed and molded is provided. Further, in Patent Document 5, engaging elements stand on an outer side of the engaging region of each fastening segment on the substrate portion, too. These outside engaging elements are buried in the cushion body which is foamed and molded, thereby fixing strength of the molded surface fastener with respect to the cushion body can be enhanced.